libstdc++-v3/include/bits/stl_stack.h

   1 // Stack implementation -*- C++ -*-
   2
   3 // Copyright (C) 2001-2014 Free Software Foundation, Inc.
   4 //
   5 // This file is part of the GNU ISO C++ Library.  This library is free
   6 // software; you can redistribute it and/or modify it under the
   7 // terms of the GNU General Public License as published by the
   8 // Free Software Foundation; either version 3, or (at your option)
   9 // any later version.
  10
  11 // This library is distributed in the hope that it will be useful,
  12 // but WITHOUT ANY WARRANTY; without even the implied warranty of
  13 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14 // GNU General Public License for more details.
  15
  16 // Under Section 7 of GPL version 3, you are granted additional
  17 // permissions described in the GCC Runtime Library Exception, version
  18 // 3.1, as published by the Free Software Foundation.
  19
  20 // You should have received a copy of the GNU General Public License and
  21 // a copy of the GCC Runtime Library Exception along with this program;
  22 // see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
  23 // <http://www.gnu.org/licenses/>.
  24
  25 /*
  26  *
  27  * Copyright (c) 1994
  28  * Hewlett-Packard Company
  29  *
  30  * Permission to use, copy, modify, distribute and sell this software
  31  * and its documentation for any purpose is hereby granted without fee,
  32  * provided that the above copyright notice appear in all copies and
  33  * that both that copyright notice and this permission notice appear
  34  * in supporting documentation.  Hewlett-Packard Company makes no
  35  * representations about the suitability of this software for any
  36  * purpose.  It is provided "as is" without express or implied warranty.
  37  *
  38  *
  39  * Copyright (c) 1996,1997
  40  * Silicon Graphics Computer Systems, Inc.
  41  *
  42  * Permission to use, copy, modify, distribute and sell this software
  43  * and its documentation for any purpose is hereby granted without fee,
  44  * provided that the above copyright notice appear in all copies and
  45  * that both that copyright notice and this permission notice appear
  46  * in supporting documentation.  Silicon Graphics makes no
  47  * representations about the suitability of this software for any
  48  * purpose.  It is provided "as is" without express or implied warranty.
  49  */
  50
  51 /** @file bits/stl_stack.h
  52  *  This is an internal header file, included by other library headers.
  53  *  Do not attempt to use it directly. @headername{stack}
  54  */
  55
  56 #ifndef _STL_STACK_H
  57 #define _STL_STACK_H 1
  58
  59 #include <bits/concept_check.h>
  60 #include <debug/debug.h>
  61
  62 namespace std _GLIBCXX_VISIBILITY(default)
  63 {
  64 _GLIBCXX_BEGIN_NAMESPACE_VERSION
  65
  66   /**
  67    *  @brief  A standard container giving FILO behavior.
  68    *
  69    *  @ingroup sequences
  70    *
  71    *  @tparam _Tp  Type of element.
  72    *  @tparam _Sequence  Type of underlying sequence, defaults to deque<_Tp>.
  73    *
  74    *  Meets many of the requirements of a
  75    *  <a href="tables.html#65">container</a>,
  76    *  but does not define anything to do with iterators.  Very few of the
  77    *  other standard container interfaces are defined.
  78    *
  79    *  This is not a true container, but an @e adaptor.  It holds
  80    *  another container, and provides a wrapper interface to that
  81    *  container.  The wrapper is what enforces strict
  82    *  first-in-last-out %stack behavior.
  83    *
  84    *  The second template parameter defines the type of the underlying
  85    *  sequence/container.  It defaults to std::deque, but it can be
  86    *  any type that supports @c back, @c push_back, and @c pop_front,
  87    *  such as std::list, std::vector, or an appropriate user-defined
  88    *  type.
  89    *
  90    *  Members not found in @a normal containers are @c container_type,
  91    *  which is a typedef for the second Sequence parameter, and @c
  92    *  push, @c pop, and @c top, which are standard %stack/FILO
  93    *  operations.
  94   */
  95   template<typename _Tp, typename _Sequence = deque<_Tp> >
  96     class stack
  97     {
  98       // concept requirements
  99       typedef typename _Sequence::value_type _Sequence_value_type;
 100       __glibcxx_class_requires(_Tp, _SGIAssignableConcept)
 101       __glibcxx_class_requires(_Sequence, _BackInsertionSequenceConcept)
 102       __glibcxx_class_requires2(_Tp, _Sequence_value_type, _SameTypeConcept)
 103
 104       template<typename _Tp1, typename _Seq1>
 105         friend bool
 106         operator==(const stack<_Tp1, _Seq1>&, const stack<_Tp1, _Seq1>&);
 107
 108       template<typename _Tp1, typename _Seq1>
 109         friend bool
 110         operator<(const stack<_Tp1, _Seq1>&, const stack<_Tp1, _Seq1>&);
 111
 112     public:
 113       typedef typename _Sequence::value_type                value_type;
 114       typedef typename _Sequence::reference                 reference;
 115       typedef typename _Sequence::const_reference           const_reference;
 116       typedef typename _Sequence::size_type                 size_type;
 117       typedef          _Sequence                            container_type;
 118
 119     protected:
 120       //  See queue::c for notes on this name.
 121       _Sequence c;
 122
 123     public:
 124       // XXX removed old def ctor, added def arg to this one to match 14882
 125       /**
 126        *  @brief  Default constructor creates no elements.
 127        */
 128 #if __cplusplus < 201103L
 129       explicit
 130       stack(const _Sequence& __c = _Sequence())
 131       : c(__c) { }
 132 #else
 133       explicit
 134       stack(const _Sequence& __c)
 135       : c(__c) { }
 136
 137       explicit
 138       stack(_Sequence&& __c = _Sequence())
 139       : c(std::move(__c)) { }
 140 #endif
 141
 142       /**
 143        *  Returns true if the %stack is empty.
 144        */
 145       bool
 146       empty() const
 147       { return c.empty(); }
 148
 149       /**  Returns the number of elements in the %stack.  */
 150       size_type
 151       size() const
 152       { return c.size(); }
 153
 154       /**
 155        *  Returns a read/write reference to the data at the first
 156        *  element of the %stack.
 157        */
 158       reference
 159       top()
 160       {
 161         __glibcxx_requires_nonempty();
 162         return c.back();
 163       }
 164
 165       /**
 166        *  Returns a read-only (constant) reference to the data at the first
 167        *  element of the %stack.
 168        */
 169       const_reference
 170       top() const
 171       {
 172         __glibcxx_requires_nonempty();
 173         return c.back();
 174       }
 175
 176       /**
 177        *  @brief  Add data to the top of the %stack.
 178        *  @param  __x  Data to be added.
 179        *
 180        *  This is a typical %stack operation.  The function creates an
 181        *  element at the top of the %stack and assigns the given data
 182        *  to it.  The time complexity of the operation depends on the
 183        *  underlying sequence.
 184        */
 185       void
 186       push(const value_type& __x)
 187       { c.push_back(__x); }
 188
 189 #if __cplusplus >= 201103L
 190       void
 191       push(value_type&& __x)
 192       { c.push_back(std::move(__x)); }
 193
 194       template<typename... _Args>
 195         void
 196         emplace(_Args&&... __args)
 197         { c.emplace_back(std::forward<_Args>(__args)...); }
 198 #endif
 199
 200       /**
 201        *  @brief  Removes first element.
 202        *
 203        *  This is a typical %stack operation.  It shrinks the %stack
 204        *  by one.  The time complexity of the operation depends on the
 205        *  underlying sequence.
 206        *
 207        *  Note that no data is returned, and if the first element's
 208        *  data is needed, it should be retrieved before pop() is
 209        *  called.
 210        */
 211       void
 212       pop()
 213       {
 214         __glibcxx_requires_nonempty();
 215         c.pop_back();
 216       }
 217
 218 #if __cplusplus >= 201103L
 219       void
 220       swap(stack& __s)
 221       noexcept(noexcept(swap(c, __s.c)))
 222       {
 223         using std::swap;
 224         swap(c, __s.c);
 225       }
 226 #endif
 227     };
 228
 229   /**
 230    *  @brief  Stack equality comparison.
 231    *  @param  __x  A %stack.
 232    *  @param  __y  A %stack of the same type as @a __x.
 233    *  @return  True iff the size and elements of the stacks are equal.
 234    *
 235    *  This is an equivalence relation.  Complexity and semantics
 236    *  depend on the underlying sequence type, but the expected rules
 237    *  are: this relation is linear in the size of the sequences, and
 238    *  stacks are considered equivalent if their sequences compare
 239    *  equal.
 240   */
 241   template<typename _Tp, typename _Seq>
 242     inline bool
 243     operator==(const stack<_Tp, _Seq>& __x, const stack<_Tp, _Seq>& __y)
 244     { return __x.c == __y.c; }
 245
 246   /**
 247    *  @brief  Stack ordering relation.
 248    *  @param  __x  A %stack.
 249    *  @param  __y  A %stack of the same type as @a x.
 250    *  @return  True iff @a x is lexicographically less than @a __y.
 251    *
 252    *  This is an total ordering relation.  Complexity and semantics
 253    *  depend on the underlying sequence type, but the expected rules
 254    *  are: this relation is linear in the size of the sequences, the
 255    *  elements must be comparable with @c <, and
 256    *  std::lexicographical_compare() is usually used to make the
 257    *  determination.
 258   */
 259   template<typename _Tp, typename _Seq>
 260     inline bool
 261     operator<(const stack<_Tp, _Seq>& __x, const stack<_Tp, _Seq>& __y)
 262     { return __x.c < __y.c; }
 263
 264   /// Based on operator==
 265   template<typename _Tp, typename _Seq>
 266     inline bool
 267     operator!=(const stack<_Tp, _Seq>& __x, const stack<_Tp, _Seq>& __y)
 268     { return !(__x == __y); }
 269
 270   /// Based on operator<
 271   template<typename _Tp, typename _Seq>
 272     inline bool
 273     operator>(const stack<_Tp, _Seq>& __x, const stack<_Tp, _Seq>& __y)
 274     { return __y < __x; }
 275
 276   /// Based on operator<
 277   template<typename _Tp, typename _Seq>
 278     inline bool
 279     operator<=(const stack<_Tp, _Seq>& __x, const stack<_Tp, _Seq>& __y)
 280     { return !(__y < __x); }
 281
 282   /// Based on operator<
 283   template<typename _Tp, typename _Seq>
 284     inline bool
 285     operator>=(const stack<_Tp, _Seq>& __x, const stack<_Tp, _Seq>& __y)
 286     { return !(__x < __y); }
 287
 288 #if __cplusplus >= 201103L
 289   template<typename _Tp, typename _Seq>
 290     inline void
 291     swap(stack<_Tp, _Seq>& __x, stack<_Tp, _Seq>& __y)
 292     noexcept(noexcept(__x.swap(__y)))
 293     { __x.swap(__y); }
 294
 295   template<typename _Tp, typename _Seq, typename _Alloc>
 296     struct uses_allocator<stack<_Tp, _Seq>, _Alloc>
 297     : public uses_allocator<_Seq, _Alloc>::type { };
 298 #endif
 299
 300 _GLIBCXX_END_NAMESPACE_VERSION
 301 } // namespace
 302
 303 #endif /* _STL_STACK_H */